                Patent Document 1: JP 2002-193046 A (corresponding to US2002/0032048)        
Patent document 1 describes a technology to connect a Bluetooth (trade marks, referred to as “BT”) communication link to thereby transmit data registered in a cellular phone to an in-vehicle handsfree apparatus.
The BT communication standard includes profiles such as a handsfree profile (HFP) for executing a handsfree communication using a cellular phone and an audio visual profile (AVP) for executing a music data transfer. Incidentally, in recent years, an in-vehicle handsfree apparatus is required which has a function (referred to as a function for multi-profile connection) to connect a handsfree profile with each of multiple cellular phones at the same time.
When such an in-vehicle handsfree apparatus having a function of a multi-profile connection is realized, the following case may arise. While an in-vehicle handsfree apparatus connects a handsfree profile (HFP) with a first cellular phone, an audio visual profile (AVP) connection with a second cellular phone is requested and the AVP is connected with the second cellular phone. When generating the connection request of the AVP, a certain type of a cellular phone also issues a connection request of the HFP according to the specification thereof. Thus, the handsfree apparatus dare to connect the HFP with both the first and second cellular phones. Herein, there is a possibility that the first cellular phone and the second cellular phone receive incoming call signals. If the first cellular phone and the second cellular phone receive incoming call signals simultaneously, a call control to the incoming call signals simultaneous occurring cannot be performed.
To anticipate the above case, when an audio visual profile (AVP) connection with a second cellular phone is requested while a handsfree profile (HFP) is connected with a first cellular phone, it may be assumed that the handsfree apparatus permits the connection request of the AVP while refusing the connection request of the HFP even if it is issued. However, a certain type of a cellular phone has the specification which cannot cut the AVP connected with the second cellular phone if the connection request of the HFP is refused. The connection request of the HFP from the second cellular phone cannot be thus refused.